Method and apparatus for spinning artificial filamentous products



METHOD AND APPARATUS FOR SPINNING ARTIFICIAL FILAMENTOUS PRODUCTS Filed July 7, 1945 1948- E. D. COPSON ET'AL 2,4573% INVENTO/ES. fE/VEST a. co sa/v 1905527 1' TA 2 as.

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A TTOENE 3- Patented Dec. 28, 1948 METHOD AND APPARATUS iron SPINNING ARTIFICIAL FILAMENTOUSPRODUCTS Ernest D. Copson and Robert Iii-Taylor, Claymont,

-Del., ass'ignors to American Viscose Corporation, Wilmington, =Del., a acorporation of Dela- Application July 7, .1943,"-s-eris1 No. 493,712 8 Claims. (01-. 118-'--8l Thisinvention is a modification of themethods and or the apparatus of cop'ending applications Serial No. 479,889, filed March 20, 1943, now Patent 2,399,258, dated April 30, 1946, Serial No. 489,071, filed May 29, 1943, now Patent 2,399,259, dated April 30, 1946, and Serial No. 490,009 filed June 8, 1943, now Patent 2,399,260, dated April 30, 1946, and is particularly concerned with the production, processing, and collection of continuous filamentary materials While maintaining them in the form of a thin web-like sheet in which the component filaments exhibit a considerable degree of intercrossing though generally extending in the direction of the length of the sheet. In my copending applications, there are disclosed arrangements of apparatus and methods for spinning continuous artificial filaments in the formof a multiple-filament bundle which is collected within the spinning bath While condensing the multiple-filament bundle along one direction only so that it is wound, with or without traverse, as a series of convolutions of a thin web-like sheet. The wound band, comprising the 'ccnvolutions of the web-like sheet upon itself, is slit transversely of its annulus, laid out in a flat condition, dried and then stretched with respect to its widthwhile maintaining longitudinal tension along its two sides. In both of such earlier applications, the subsequent drying and expansion of the dried wound band with respect to its width gives rise to novel products of extremelyilight-weight andlfiuffiness which are useful as heat and sound insula tion, vibration damping material, cushioning material, buoyant material and the like. In accordance with the present invention, there is provided a novel arrangement of apparatus which makes it possible to subject filaments spun in one bath to an after-stretching or to any other processing treatment in aseparate bath while still maintaining the filaments in the form of a weblike sheet which may comprise a plurality of layersof intercrossing filaments. This is especially important when dealing with extremely fine diameter filaments because such filaments are generally severely damaged if attempts are made to re-open a condensed yarn-like bundle thereof. While the particular conditions and theparticular materials disclosed .for use in executing the method will be described hereinafter with particular reference to the spinning of hydrophobic synthetic linear polymers it is to be understood. that the apparatus is applicable as well to the spinning of other materials such as cellulose acetate, viscose, and the like.

'In'the drawing, illustrative of the invention,

Figure 1 is an elevation, partiall in cross-section, of one embodiment of the invention,

Figure 2 is a plan view'of the embodiment Figure 1, and

Figure 3 is an elevation, partially in cross-sectionofanotherembodiment.

As shown in Figures 1 and 2 of the drawing, filaments in the form of a multiple-filament bundle proceed from the spinner-ct? throughafunnel guide '3 adjacent to it, then through a second funnel guide 4 which has a large internal diameter to control the width of the band Or Web-like sheet of the filaments at the point of contact with a guide roll 5 adjacent thereto and partially immersed within the coagulating bath 6. From this guide roll 5, the filaments proceed still as a Weblike sheet about a second'guide roll 1 which overhangs the coagulating bath 6 and also asecond.

bath 8 which may contain a plasticizing or other processing liquid. From the second guide roll 1, the web-like-sheet proceeds to a third guide roll 9 partially immersed within the second bath 8 and thence to another guide roll l0 "partially immersed therein, and finally from the latter to a suitable take-up device 0r drum H. The various guide rolls are sufiiciently wide to carry the desired width of the web-like sheet of filaments which'it is desired to transfer from the bath 6 to the other bath 8 and finally to the take-up device H. It is essential that the adjacent guide rolls between which the sheet of filaments extends while outside of the liquid be closely positioned to one another to prevent disruption of the web-like sheet into more or less distinct filament bundles because of th'e surface tension of the liquid carried thereby. :In order to accomplish this, the adjacent guide rolls (for example, :5 and I, or I! and 9, or I1] and l I) should be positioned sufiiciently close to one another that the course of filaments extending between the points of contact with one roller and the point of contact with the adjacent roller is not greater than approximately 50% of the width of the sheet nor more than 6 inches. Preferably, even closer juxtaposition of not over 2 to 3 inches is employed. If desired, 'a funnel guide similar to guide i in proximity to the first guideroll may be placed in advance of the guide roll 10 in the second loath to prevent spreading of the filaments to .a greater width than that desired. All of the guide rolls are driven at constant speed except when it is desired to stretch or relax the filaments as a web-like sheet in the second bath in which event, the last guide roll ['0 within that bath is driven at a higher or lower linear peripheral speed respectively than the preceding roll 9. Relaxation in a plasticizing bat-h efiects crimping of the filaments in the web. while stretching effects some reduction in size of the filaments and an increase in tenacity.

In Figureli, there is shown a modification in whichthe filaments proceeding from a suitable source, such as a spinneret (not shown), pass which-narrows down to the form of'a slit elongated in an approximately horizontal direction. The guide l2 secured in liquiditight fashion to the end wall l3 of the container for the liquid bath, which may be the coagulating bath 6 of the embodiment shown in Figures 1 and 2 or any other treating bath in such a manner that its elongated slit serves as an exit from the container. The filaments still in the form of a weblike sheet carrying substantial amounts of water pass immediately from the discharge opening of guide I2 through a pair of rolls M which are rotated in the direction shown and are so closely spaced as to prevent the passage of any large quantity of liquid with the filamentary sheet without exerting any pressure on the sheet, The rolls M are supported in a housing l secured to the wall l3, suitable packings and roll-contacting doctors being provided betweent the housing and rolls to minimize leakage. The filaments still as a web-like sheet then proceed into the next processing bath through an entrance comprising a pair of rolls l5 rotated in the direction of the arrows in a housing I! provided with suitable liquid seals and a horizontally elongated opening in the wall l8 of the container for the next processing bath, such opening constituting the entrance of the funnel guide [9. The travel of the filamentary sheet through the guide I9 tends strongly to reduce the escape of liquid from this entrance channel. Between the two walls 13 and 18, an intermediate chamber is formed which is divided into two sections by a partition 20 which makes it possible to keep separate any overflow or leakage from the adjacent bath containers. Separate drains 2i and 22 may be provided to return the overflows into their respective recirculation systems.

It is thus possible to provide for the processing of the artificial filaments while in a web-like sheet in an after-treatment bath of any composition or under any conditions entirely independent of the particularmaterial in the coagulating bath and the conditions therein. The subsequent bath may be used to after-stretch or to crimp hydrophobic synthetic linear polymers, such as the vinyl resins disclosed in my copending applications referred to above. Alternatively, where filaments of protein are involved, the after-treatment bath may be a washing or hardening bath; in the case of viscose, it may be a processing bath, such as a washing or it may be a plasticizing bath to facilitate after-stretching between the guide rollers therein or may serve several of these purposes simultaneously.

The distance between the guide rolls 9 and [0 in the after-treatment bath may be adjusted to any desired extent. This arrangement is especially advantageous when making fine filaments in accordance with the procedures disclosed in my copending applications referred to above in that the spinning solution ofwatery consistency may be extruded into a relatively short coagulating bath with a low jet stretch and then introduced into a stretch bath without disturbing the weblike formation of the filaments. For some purposes, as where washing is being performed, the second guide {0 in the secondbath may be replaced by a take-up device.

As an illustrative example of the application of the arrangement of the present invention, a solutionin acetone of a low concentration of a copolymer of vinyl chloride and vinyl acetate having a watery consistency is extruded through a BOOOone-mil hole spinneret 2 into a coagulating 'bath i-thrcughiunnel guides 3 and 4 having 4 a minimum internal diameter of two inches. The coagulating bath was maintained at 45 C. and the travel of the filaments from the spinneret 2 to the first part of contact with the guide roll 5 was 12". The guide rolls 5 and 9 were placed within one inch from roll I as measured by the course of the filamentary sheet between them. The filamentary sheet proceeded to the second bath 8 of water in which a temperature of 80 C. was maintained and in which the difierence in speeds between the guide rolls 9 and H] was such as to impart stretch of about 500% therebetween, the linear speed of guides -5, 1 and 9 being such as to produce an initial jet stretch of 1000%. The band of wound filamentary sheet is cut from the take-up device and allowed to dry after bein laid out flat. Then the band was stretched in the direction of its width in order to produce a flufied and expanded mat of the type disclosed in the earlier patent applications referred to above.

A similar mat of light weight was produced in accordance with the procedure of the preceding paragraph with the exception that guide roll 10 was operated at a linear speed less than that of roll 9 so that a product was obtained in which the filaments were crimped throughout the product in substantially uniform manner.

While preferred embodiments of the invention have been disclosed, it is to be understood that changes and variations may be made without departing from the spirit and the scope of the invention as defined by the appended claims.

We claim:

1. In apparatus for producing artificial filamentous products, a liquid coagulating bath, a spinneret therein, an after-treating liquid bath, guide rollers having substantially smooth cylindrical peripheral surf-aces of substantial breadth partially immersed in adjacent ends of the respective baths for receiving and maintaining the filaments proceeding from the spinneret as a web-like sheet, and another guide roller having a substantially smooth cylindrical peripheral surface of substantial breadth arranged outside the bath with its peripheral surface in close proximity to, but out of contact with, the surfaces of the first-mentioned rollers such that the air travel of the web-like sheet between adjacent rollers is not over 50% of the width of the sheet nor over 6 inches.

2. In apparatus for producing artificial filamentous products, a liquid coagulating bath, a spinneret therein, an after-treating liquid bath, guide rollers having substantially smooth cylindrical peripheral surfaces of substantial breadth partially immersed in adjacent ends of the respective baths for receiving and maintaining the filaments proceeding from the spinneret as a web-like sheet, and another guide roller having a substantially smooth cylindrical peripheral surface of substantial breadth arranged outside the bath with its peripheral surface in close Proximity to, but out of contact with, the surfaces of the first-mentioned rollers such that the air travel of the web-like sheet between adjacent rollers is not over 50% of the width of thesheet nor over 6 inches, a fourth guide roller having a substantially smooth cylindrical peripheral surface partially immersed in the after-treatment bath and spaced from the other roller therein, and take-up means in close proximity to the fourth guide roller for winding the web-like sheet delivered therefrom.

3. In apparatus for producing artificial filamentous products, a liquid coagulating bath, a

spinneret therein, an after-treating liquid bath, guide rollers having substantially smooth cylindrical peripheral surfaces of substantial breadth partially immersed in adjacent ends of the respective baths for receiving and maintaining the filaments proceeding from the spinneret as a web-like sheet, and a third guide roller having a substantially smooth cylindrical peripheral surface of substantial breadth arranged outside the bath with its peripheral surface in close proximity to, but out of contact with, the surfaces of the first-mentioned rollers such that the air travel of the web-like sheet between the adjacent rollers is not over 50% of the width of the sheet nor over 6 inches, a fourth guide roller having a substantially smooth cylindrical peripheral surface partially immersed in the aftertreatment bath and spaced from the other roller therein, means for driving the fourth roller at a linear peripheral speed greater than the other rollers to effect stretching of the sheet in the after-treatment bath, and take-up means in close proximity to the fourth guide roller for winding the web-like sheet delivered therefrom.

4. In apparatus for producing artificial filamentous products, a liquid coagulating bath, a spinneret therein, an after-treating liquid bath, guide rollers having substantially smooth peripheral surfaces of substantial breadth partially immersed in adjacent ends of the respective baths and a third guide roller having a substantially smooth peripheral surface of substantial breadth arranged outside the bath with its peripheral surface in close proximity to, but out of contact with, the surfaces of the firstmentioned rollers such that the air travel of the web-like sheet between the adjacent rollers is not over 50% of the width of the sheet nor over 6 inches, a fourth guide roller having a substantially smooth peripheral surface partially immersed in the after-treatment bath and spaced from the other roller therein, means for driving the fourth roller at a linear peripheral speed less than the other rollers to effect relaxation of the sheet in the after-treatment bath, and take-up means in close proximity to the fourth guide roller for winding the web-like sheet delivered therefrom.

5. The method of making artificial filamentous products comprising extruding a plurality of filaments into a liquid coagulating bath, withdrawing the filaments from the position of extrusion under conditions of turbulence causing the paths of the filaments to overlap each other irregularly as viewed in a vertical direction condensing the filaments while in the coagulating bath to a web-like sheet containing intercrossing filaments, conducting the web-like sheet out of the coagulating bath and introducing the filaments still in the form of a web-like sheet containing intercrossing filaments into a second liquid bath.

6. The method of making artificial filamentous products comprising extruding a plurality of filaments into a coagulating liquid bath, withdrawing the filaments from the position of extrusion under conditions of turbulence causing the paths of the filaments to overlap each other irregularly as viewed in a vertical direction,

condensing the filaments while in the coagulatand collecting the filaments by winding them while still in the form of a web-like sheet containing intercrossing filaments.

7. The method of making artificial filamentous products comprising extruding a plurality of filaments into a liquid coagulating bath, withdrawing the filaments from the position of extrusion under conditions of turbulence causing the paths of the filaments to overlap each other irregularly as viewed in a vertical direction, condensing the filaments while in the coagulating bath to a web-like sheet containing intercrossing filaments, conducting the web-like sheet out of the coagulating bath, introducing the filaments still as web-like sheet containing intercrossing filaments into a plasticizing liquid bath, stretching the filaments as they pass through the plasticizing bath still in the form of a Web-like sheet containing intercrossing filaments, and collecting the filaments by winding them while still in the form of a web-like sheet containing intercrossing filaments.

8, The method of making artificial filamentous products comprising extruding a plurality of filaments into a liquid coagulating bath, withdrawing the filaments from the position of extrusion under conditions of turbulence causing the paths of the filaments to overlap each other irregularly as viewed in a vertical direction, condensing the filaments while in the coagulating bath to a web-like sheet containing intercrossing filaments, conducting the web-like sheet out of the coagulating bath, introducin the filaments still as a web-like sheet containing intercrossing filaments into a plasticizing liquid bath, relaxing the filaments as they pass through the plasticizing bath still in the form of a web-like sheet containing intercrossing filaments, and collecting the filaments by winding them while still in the form of a web-like sheet containing intercrossing filaments.

ERNEST D. COPSON. ROBERT J. TAYLOR.

REFERENCES CITED The following references are of record in the file of this patent:

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